Hemodialysis is a process in which an external machine is used to filter blood to remove excess salt and harmful wastes. For example, blood may be sent to a hemodialysis machine and back to the patient's circulation. The blood may enter and exit a body via a vascular access. For instance, a vascular access for the blood may be created by introducing cannulas into a patient's vein. Blood may then be sent to a hemodialysis machine and back to the patient's circulation via the cannulas. To enable ease of cannulation and ensure availability of many candidate access sites, a larger vein may be used. This may be possible by shunting arterial blood flow through veins. Two kinds of vascular access procedures include—arteriovenous fistula (AVF) (in which an artery and a vein may be directly connected) and arteriovenous graft (AVG) (in which a synthetic graft may be attached between an artery and a vein). Demand for cardiac output may change from before and after treatment (e.g., pre- and post-shunting of blood flow). For example, the arteriovenous connection may increase blood pressure and blood flow in the veins. The veins may slowly adapt to this shunting by enlarging in diameter and increasing in thickness. This adaptation process might take anywhere from one month to a year. Once adapted, many different candidate sites may be available for repeated cannulation and hemodialysis.
However, the change in cardiac workload for the heart post-treatment may create a health risk. For instance, shunting the blood flow from an artery to a vein may reduce overall system resistance, thus changing hemodynamics in a way that increases cardiac output. This increased demand for cardiac output may result in a larger workload for the heart, and may be linked to an increased risk of congestive heart failure. Further, treatment may change vessel geometry, thus altering regions in vessels that may be prone to thrombosis. An optimal AVG may minimize regions of disturbed hemodynamics and, consequently, minimize regions prone to thrombosis.
Thus, a desire exists to ensure that there is enough blood flow to allow successful dialysis and maintain sufficient perfusion to extremities, and at the same time, ensure that change to hemodynamics is minimal so that cardiac demand may not increase to a point that endangers a patient. Furthermore, a desire exists to improve treatment planning by optimizing vascular access graft locations and/or vascular access graft types. The present disclosure is directed to improving treatment planning by predicting changes in hemodynamics that may result from vascular access procedures.
The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.